Answer to Question 1
Searle and Bennett reviewed a decade of literature between 1990 and 2000 that included 14 papers on a related though more serious condition called inflammatory bowel disease (IBD). Whereas IBS is a functional disease that eludes detection with traditional testing, IBD always has visible inflammation of the intestinal lining that is seen through x-ray or colonoscopy. IBD is a broad term that incorporates both Crohn's disease (CD) and ulcerative colitis (UC).
Answer to Question 2
Allergic rhinitis (AR) sufferers have allergic reactions to certain pollens, dust particles, or airborne chemicals. Symptoms include itchy, watery, or burning eyes; nasal congestion; loss of smell or runny nose; stuffy head; headaches over the paranasal area (alongside the nose); blunted taste; an itchy roof of the mouth; dry cough; sore throat; drainage down the back of the throat; itchy ears; or a full or plugged feeling in the ears.